Cush drive Mk1 how oes it fit

[Graeme.crawley]

I have started on my basket case Sq4. To see if I had the correct gearbox I assembled the grankcase and the rear crank bolted in the Gearbox and the rear wheel and unfortunately the gearbox appears to be 1/4 inch too far towards the timing side. I have a mainshaft that is about 1/2 inch longer than the one that was in the gearbox but I undertand that the actual caseing has the upper and lower mountings set 1/4 inch different to the standard gearbox and indeed this seems to be the case with my box - If this is in fact true then I need a MK BA gearbox case from somewhere. But in assmebling all this I found the cush drive outer ramp will not push all the way home into the sleeve section that the sprocket run around on. The high point of the ramp Humps refuse to go over a lip on the sleeve. I have two like this. Is this some issue that strain over time creates or maybe I have completly unmatched parts even though I have two the same (well they are not 100% the same the Sleeve differs and the Ramp looks a bit different but has the same dimensions.
I imagine the ramp is hard so it is likely to be a struggle to skim a bit out of the ramp even though it seems to be a miniscule amount. PS - even a hammer failed to move the tips of the ramp over the sleeve's lip so it must be more than a thou or so. Cant get a picture to show, will try attachment
Graeme

[john.whiting]

just get a cylindrical stone and stone off the burrs.....it may be too hard for a file.......The theory of mass production and interchangeable parts says it was OK when new.

[simon.holyfield]

Have a look at this - the second picture:

https://ariel-square-four.blogspot.com/ ... orror.html

Is that sleeve the right one?

[roger.fellows]

There is a photo of the sleeve on Drags' website even though it is out of stock.

Make sure that you have the correct sprocket, too. My late father's machine had been assembled with a Huntmaster sprocket - tightening the shock absorber squeezed the sprocket against the coupling gear cover.

Club spares may have any bits you need.

[john.mitchell]

You need to be a member to access Club spares. As a non profit Charity we are not allowed to sell spares outside the club.

[Graeme.crawley]

Hello John
Yep have been a member for many years. Unless you have a MK1 Sq4 gearbox shell I was not thinking I needed any spares but as one person said, do I have the right sleeve? Well I do not know; this is first SQ4 I have owned. The cush is the same principle as my Huntmaster but not the same to look at and as I noted I have two of these things and both do not fit together into the sprocket ramps as I expected which made me think I have something like a spacer missing or such like. It seems that this is not the case so I shall open out the Ramp internal ID with a tungstan tool until it does fit over the sleeve properly. But thanks for the advice on the sprocket teeth count - I will check this tomorrow morning, possibly the wrong sprocket is the issue. Graeme

[roger.fellows]

Graeme, I believe the sleeve is wrong, as Simes suggests.
I cannot tell from your photo, but the sleeve seems to have a wider rim at the end.
It should be uniform OD at both ends. That sleeve looks too short.

[roger.fellows]

If you email the webmaster with your membership number your name will appear in red to signify your status.

[roger.fellows]

Before you resort to the lathe or Black-Country screwdriver, these photos should show that the sleeve will pass completely through the sprocket. It can be inserted into the sliding member from the engine side until stopped by the splines in the sliding member.

There are different sets which can form the assembly as you probably know. I think it would be worth using a set with a castellated nut, for security.

Ask for more photos if you want to see anything more clearly.

[roger.fellows]

The top photo above showing the specially shaped washer and castellated nut does not show the order/orientation when assembled, before anybody points that out. ..

I should also say mine is MkII, but I believe these items would fit MkI.